This invention relates to novel estriol esters, to processes for their production, and to pharmaceutical preparations containing them.
Estriol, 1,3,5(10)-estratriene-3,16.alpha.,17.beta.-triol, is an important natural estrogen. It is also utilized as the active ingredient in preparations for estrogen substitution in cases of estrogen deficiency, for example in postmenopausal women. Since estriol is very rapidly eliminated from the body, it must be administered in short intervals (one to three times daily).
Several esters of estriol have also been described in the literature, for example estriol triesters, 16,17-diesters and 16-monoesters in Chem. Pharm. Bull. 11: 510-514 (1963), as well as 3-acetate, 3,16-diacetate, and 16,17-diacetate in Acta Chem. Scand. 22: 254 (1968). With the exception of estriol succinate, which must be administered three times daily, no estriol esters have been utilized as medicines.